If a frequency polygon has class midpoints labeled as 20, 40, 60, and 80, what does a point at x=60 and y=20 represent?

• A. The class with midpoint 60 has a frequency of 20.
• B. There are 20 individuals exactly at age 60.
• C. The class with midpoint 60 has a frequency of 60.
• D. The class with midpoint 60 has a cumulative frequency of 20.